Vacuum seal, method and apparatus



Aug. V1w 192s. i 1,595,238

o..M|NToN vAcuw SEAL, METHOD AND APPARATUS Filed Feb. 7. 1922 7 Sheets-Sheet 1 .N 1 i n A Q A 24,

g ZINVSQEN TOR I A TORN Y Aug. 10 1926. 1,595,238

I o. MxNToN VACUUM SEAL, METHOD AND APPARATUS Filed Feb. '7, 1922 7 Sheets-Sheet 2 ffyz )N NTOR T ORNE Aug. V10 1926.

N www... l IM 1 4 7 Sheets-Sheet 5 :NVE/v lok `ALTTURNEI 0. MINTON VACUUM VSEAL, METHOD AND'. APPARATUS Flled Feb 7 1922 lo N q 0 n E m v 1!) I um, um, u SNN a .R0 *Nw ug. A10 1926.

Filed Feb. 7, 1922 7 Sheets-Sheet 4 NMS R O T N E N l..

A TTORNEY Aug. 10,1926. 1,595,238 O. MINTON VACUUM SEAL, METHOD AND APPARATUS Filed Feb. 7, 1922 '7 Sheeos-Sheell 5 Aug. 10 1926. 1,595,238

l o. MmToN vAcuun SEAL, nsron AND APPARATUS Filed Feb. 7, 1922 7 Sheets-Sheet 6 v lll/1111111111111',

1,595,238 O. MINTON VACUUM SEAL, METHOD AND APPARATUS Filed Feb. '7, 1922 '7 Sheets-Sheet 7 Aug. l0 1926.

mu 'i Patented Aug. 1o, 1926.

vPATENT OFFICE,

OGDEN MINTON, OF GREENWICH, CONNEQTICUT.

VACUUM SEAIa-METHOD AND APPARATUS. l

, Appiic'ation mea February 7, 1922. sei-m1 No. 534,812.

This application is for a species of my invention covered broadly in my copending `applicatio-n Ser. No. 427,436, filed November 30, 1920, and is alsoy covered in the divisional application of said case filed' Jan. 21, 1922, Ser. No. 530,990, case Q.

"My linvention relates to the method of treating materials in a vacuum, and more particularly to the method of protecting theopening oropenings 4into the vacuum chamber, through which opening or openings the material to be treated is introduced Aand Withdrawn from the chamber.-

More particularly it relates 'to restricting theV entrance vand exit passages of the vacuum chamber by a moving member or members, as for example one or more rolls, mounted Within the entrance and exit passages, making the roll or rolls substantially cloffe the passage-in which it, or they, are

mounted leavin-g, sufficient clearance to permit the free passage of a web of sheet material, and also the -free passage of oneor more carrier' belts ifthese are used; and making the entrance and exit passages substantially air tight by employing any suitable fluid as a sealing medium. This sealing fluid has more or less How, drip or seepage into the vacuum' chamber depending principally upon the degree to which the entrance and exit passages are closed vby the one'or more rolls mounted in each passage. Ifv the roll or rolls in the entrance and exit passages, together'with the single or plural carrier belts and the web yof paper or other sheet material substantially close the passage, the Huid -will merely drip vor seep through into the vacuum chamber. If, however the parts fit loosely more of the sealing Huid Will .work into the vacuum chami ber 'and the uid vvilll have more or less. fi'ow. It is desirable to restrict the 110Wl of the fluid .as much as possible consistent with the successful ope-ration of the method and apparatus as a whole. y

'I he sealing fluid may be one'which has an affinity or attraction fo other sli-eet material being treated, as for example Water or similar liquid; or, the sealing fluid may be onevvhich has no attraction or ainity for the web of paper orother sheet' material to be treated in the vacuumchamber; such a liquid; for example, as

mercury or an amalgam or other suitable material.

If the sealing fluid has an 'attraction f or ments, whereby the paper, or,

'method of drying any sheet material in a Vacuum chamber; Whether such material be Woven fabric or'not. It relates more particularly to drying -a vcontinuous web of paper 'either coming from the Wet end of a paper machine, or from a sizing vat, or

from a coloring apparatus, coating machine v or printing machine or directly from a roll of Wet paper.

My invention further relates to drying lthe fabric, paper or other sheet material, in the vacuum chamberby drying drums or cylinders, or any other suitable means mounted inthe vacuum Chamber.-

When drying drumsv or cylinders are used my invention further relates to employingy with each drying drum or cylinder a separate individual felt, so that drying rolls may 'be driven at different speeds to compensate for different lshrinkage on the different drying drums or cylinders. J My invention further relates to steps and combinations of steps, also to certain elements and combinaticns of elethe method or processes herein describedmay be carried out, as Well as to certain details of Construction, all of which will be more fully hereinafter described in the specification and pointed out in the claims.

Various forms of apparatus may be employed to carry out my improved method. The number of the/rolls and the number of the carrier belts may carrier belts maybe omitted; the sealing liquid may be varied.; different means may be used to retard, or increase the flow of the sealing liquid into the vacuum chamber;

.diierent means may be used to withdraw vacuum chamber; one sealing liquid may be used at the entrance'to the vacuum chamber,

be varied; or the' certain and a different sealing liquid-may be used at the exit passage as may be found convenient or expedient; and other various changes may be made without departing from the scope of my invention as dcrlbed. in the specification and claims.

' I have shovvn inthe accompanying draw- I of another form of ings various forms of apparatus, which may be used to carry out my improved method, but it is to be distinctly understood that these forms are simply shown by way of example and are diagrammatic, and that my invention is not to be confined to them.

In the accompanying drawings the same reference numerals refer to. similar parts in the several figures.

Fig. 1 is a diagrammatic view showing one form of my invention in which two carrier or protecting belts are used to carry and protectthe web while it passes through the liquid seal;

Fig. 2 is a diagrammatic sectional fragmentary view, of another form, similar to the first, except that only one carrier belt is employed to guard and protect the Web in its passage through the liquid seal;

Fig. 3 is a detail cross section through the two protecting water-proof carrier belts and the web;

Fig. 3Il is a detail cross section of amodification showing interlocking carrier belts;

Fig. 4 is a detail cross section on line L1`4= of Fig. 2, showing the use of one. carrier belt or felt, the housing being omitted;

Fig. 5 is a vertical diagrammatic view apparatus shown by way of example; f F.F ig. 6 is a vertical section on line 6 6 of Fig. 7 is a diagrammatic vertical section of another and the preferred form of my apparatus, which may be used to carry out Vmy method;

Fig. 7El is a vertical section of the preferred form shown in Fig. 7, showing particularly how the sealing iuid works around the ends of the sealing rolls and is taken substantially on the line 73- a of Fig. 7, looking in the direction of the arrows;

Fig. 8 is a fragmentary detail vertical secieqn of another form of seal and carrier Fig. 9I is a diagrammatic fragmentary section showing still another arrangement of sealing rolls and carrier belts; t

Fig. 10 is a diagrammatic fragmentary section showing -still another arrangement of sealing rolls and carrier belts;

11 is a detail section on line 11-11 of Fig. 12 is a detail section on line 12-12 of Fig. 9;

Fig.- 13 is a diagrammatic vertical section of 'still another modification Yof my invention.

The vacuum chamber A has al vacuum Y.

maintained therein in any suitable manner by connecting the pipes 1, 1 with anysuitable exhausting apparatus. This vacuum chamber has an entrance and' anexit passage. Through these passages the material to be treated in the vacuum chamber A is introduced and withdrawn. Of course, if the passages were left unguarded too lmuch air would leak into the chamber to feasibly maintain a vacuum.

My present invention broadly consistsin restricting the entrance and exit passages by one or more movable members in connection with a liquid so that the movable member or members and the sealing liquid together make the passage substantially air tight and prevent air leaking into the vacuum chamber A. These members are preferably in the form of guide rolls so that in addition to their function of restricting the passages they also act as guides for the web to be treated.

The liquid employed maybe one which has an affinity for the web,to be treated, as for example water, or the liquid may have no aiinity for the web, suchfor example as mercury, amalgam or similar liquid. When the liquid is one which has an afinity for the web it is protected in its passage through the liquid seal by oneor more Waterproof` carrier belts.

In my invention any suitable material i' may be introduced into and withdrawn from the vacuum chamber A through my Huid seals. Itmay be paper, or a woven fabric,

or any other suitable material to be dried or otherwise treated in the vacuum chamber. It may be fed through the vacuum'chamber continuously or not. I have shown by way of example the material in the form of a continuous web 2 of paper, which passes continuously through the vacuum chamber A and the fluid seals. This web maybe dried in thevacuum chamber, or coated, im- A pregnated or treated in any other suitable manner.'

` The vacuum chamber A is provided with the entrance passage 3 and the exit passage 4. These passages are substantially the same so that the description of one will sutlice f or the other. In the entrance passage 3 of Fig.

l, is mounted a roll V5, its periphery being brought as closeas posslble to the roll chamber or housing 6, the clearance being just sufficient to permit the web 2, the lower car. rier belt 11 and the upper carrier belt 7 to pass between it and the :telt roll housing 6,

together with such sealing liquid as will I work through.

This liquid 8 is fed into the roll housing 6 in any suitable manner, such .as through the nozzle 9, and seals the restricted passage 10 between the felt roll housing 6 and the felt roll 5 so that, practically no air can work into the vacuum chamber A,

As the web 2 of wet paper, or other material, passes into the sealing liquid 8 it is, in the form shown in Fi 1, protected by two waterproof carrier be ts, the-lower waters proof carrier belt 11 and the upper-water proof carrier belt 7. These wateaproofcardrying drums or 'wherein the pipe 14 is l13,595,238 l i rier belts are wider than the web and comletely enclose and protect it from contact with the liquid 8. As the web and carrier belts are fed continuously' chamber A, a small amount of the sealing liquid 8 will work under the roll 5 and into the well 12.. This liquid may be withdrawn from the vacuum chamber in any suitable manner. Preferably I permit it to flow into a barometric seal 1 3, which prevents any air working back into the vacuum chamber A.

If desired the sealing lliquid 8 may be per- A mitted to runto waste, or may be used over and over again as shown in Fig. 1, connected to the pump 15, which pumps the liquid back to the nozzle 9 and into the roll-housing 6. 'Ihe restricted passage 10 is made as small as possible ,so that comparatively little of the sealing liquid will work into the well 12.

To insure that o air 4will work past the upper surface of the roll 5'and thence into the vacuum chamber A I may pack the roll in any suitable'manner. This packing may be solid matter,` or a series of dovetailed surfaces, or the packing may be liquid orany other form of packing may be used. -I have shown in the drawings a liquid pack- -ing as for example water under pressure, :so

which is fed into the liquid seal 16. Any water that may leak between the seal 16 and the roll 5 is caught by the wipers 17 and 18, and Withdrawn 1n any suitable mannen It has been oundfin practice that the shrinkage of the'wet web of paper will vary on the ditlerent drying drums or cylinders 19, 20, 21, 22 and 23. While I have shown live cylinders mounted in my vacuum chamber A, it is of course to be understood that .any number of such dryin drums or cylinders may be used as found convenient or expedient. To compensate for this unequal shrinkage of the wet web of paper, or other material, on they drying drums or cylinders, I revolve these cylinders at varying speeds and employ separate and individual felts 24, 25, 26, 27 and 28, one for eabh 'of the drying drums or cylinders, as shown in Fig. 1, the elts passing over the guide rolls 57, 57.

After the wet web 'of paper 2, protected by the water-proof carrier belts 7 land 11, has been fed into the vacuiun chamber through the liquid seal 8 and through the restricted portion 10 of the entrance passage 3, these waterproof carrier belts are-freed from the wet web of paper 2. This permits the separate individual drying elts 24, 25,

26,27 and 28 to cooperate with the web while it is passing over and in contact with their particular drying drum or cylinder, vwhich are driven in .any well-known manner at varying speeds. In this way the different shrinkage of the web 2 on the, different drying drums and cylinders is compensated for,

into the vacuum v the liquid 8 of theV seal by which lessens the liability of breaking the webor causing what is known in the trade as broke. l f

Any suitable arrangement of the two car? rier'belts 7 and 11 may be employed. I have shown for-purposes of example, the upper carrier belt 7 after passing into the vacuum chamber A being led over the guide rolls 29, 30, 31, 32, 33, 34, 35 and 36. At the guide roll 36 the upper carrier belt 7 again meets the web 2, which is now dry, and protects it, with the aid 'of the lower carrier belty 11, as it passes out of the vacuum chamber around the second roll 5 .and through the second or exit liquid Seal 8. The upper carrier belt 7 is then passed over the guide rolls 37, 38, 39, 40 and 41 bqack to` the entrance for the vacuum chamber, its movement being con' tinuous.. u

The lower contlnuo'us carrler belt 11; afterlit passes into the vacuum chamber, passes over the guide roll 42 thence in contact with the guide lrolls 43, 44, 45 and 46, where it again meets the now dry web 2 and protects it while it passes through the second or' ex'rt liquid seal 8, as previously described. It is then guided by the rolls 47, 48, 49, 50 andl51 lback to the ertrance of the vacuum' chamber.

In some cases I may use lnterlocking carrier belts to prevent any of the sealing liquid contact-ing with -the material being dried.

I have shown for example one form of such an interlocking carrier' belt in Fig. 3

in which the upper carrier belt 207 and the lower carrier belt 2,11 are provided with interlocking surfaces. In the former shown by way of example is provided with two continuous grooves 213, 213. The upper carrier belt 207 is provided with two continuous ribs 214, 214 to fit into the grooves 213, ,213. -Wherever I employ two carrier belts they may be formed4 the lower carrier belt 211 of my invention the lower waterproof carrier belt 11 will alone protect the web yfrom pressing it against the roll 5 as shown in Figs. 2 and 4. In this form also I have-shown the well 12 connected directly with a pump linstead of using a barometric seal.

It is to be understood that different sealing liquids may be used at the same time. For example, water may be used at thefentrance to 'the vacuum chamber A, and mercury, amalgam or lany. other suitable fluid at the exit, or any 'other suitable liquids may be used.

I have shown a modification of my invention in 5 and 6. In this form of my invention protect the entrance and exit passages of the vacuum chamber by a plurality of rolls mounted in each passage.

The web 2 of paper is fed through the liquid 8 of the seal while in contact with the revolving roll 151 and pressed thereon and protected by means of the waterproof endless carrier belt 52. Beneath the roll 51, I mount the roll 53 so that these rolls together form a very restricted passage for the liquid 8 to work into the well 54 ot the vacuum chamber A. The waterproof carrier belt 52 is wider than the web ot paper 2 and is drawn taut over the roller 151 so that the web 2, including its edges, is co1npletely protected from Contact with the liquid, as is shown :tor example in Fig. 6.

After the web 2 has been introduced intothe vacuum chamber, the endless carrier belt- 52 is immediately withdrawn and passed over the guide roll 154, back under the roll '53 and out through the liquid 8 to the guide roll 55. The wringer rolls 56, 56 serve to remove any liquid that may adhere to the waterproof carrier belts 52, 52.

The wet web 2 is then passed over and in contactV with theheated drying drums or cylinders 19, 20, 21, 22 and 23. After passing over the last ydrum 23, it is completely dried and is passed out of the vacuum chamber A through the eXit passage 4, which is protected in the same manner as the entrance passage 3, so that the dry web of paper 2 does not come into contact with the liquid 8, whatever that liquid may be.

To allow for the separate shrinkage of the web upon the diti'erent drying 'drums or cylinders 19, 20, 21, 22 and 23, I preferably employ individual elts 24, 25, 26, 27 and 28, one for each of the drying drums or cylinders, as shown in Fig.5, theJ felts being guided 'over the guides *57, 57. The advantage of this has been previously described in connection with the structure shown in Fig. 1.

As previously described, the liquid 8 may be a liquid which has an aliinity for the material treated, or it may be a liquid such as.

mercury, amalgam, -or any other suitable material, all as previously noted. This is true of all forms of my invention. This liquid will flow between the rolls 151 and 53 and between the roll 53 and theportion 58 of the roll housing 59. This flow will vdepend upon the degree of vacuum maintained within the vacuum chamber A and upon the area of the restricted passage formed by the rolls 151 and 53. `With a very restricted passage, which is the preferred, construction, a comparatively smallV amount of the liquid 8 will pass through the restrictedy passage and will be caught in the well 54. Some of the'liquid will be caught by the catch basin-58 and permitted to run out through the pipe 159 around the carrier belt 52, and thence into the well 54. From this chamber it is withdrawn in any suitable manner; either being permitted to run to waste or to be used again as the liquid of the seal. For purposes of illustration, I have shown the well 54 connected by the pipe 60 with the barometric-seal 13. From this barometric seal, the liquid may be permitted to run to waste, or it may be withdrawn by the pipe 14 and pump 15 and pumped back into the roll housing. 59 to be again used as the liquid of the seal.

The dry web 2 of' paper or similar material passes from the last drying drum or cylinder and out through the exit passage, and duplicate seals, iblls and carrier belts. It is to be understood, however, that diderent sealing liquids may be used in the e11- trance and exit passages, if desired.

To prevent air working around the upper periphery of the roller 151, I may pack this roller in any suitable manner, as the rollers 5. 5 are packed in Fig. 1. In the form shown the water under pressure is fed through the pipe 63 to the liquid seal 16. The wipers 17 and 18 remove any lilm of water that may adhere to the periphery of the rolls 151, 151.

I have shown another modification of my invention in Fig. 7. In this form the entrance and exit passages to the vacuum chamber A are substantially close-d or -restricted by three rollers 64, 65 and 66.

In this form I also use a single waterproof carrier belt 67 which guards and 1protects the web 2 ot paper, or other material, by pressing it firmly against the periphery kof the roll 64. see Fig. 7 and Fig. 11, and

'Withdrawn from the web 2 and passed around the roll 65, thence out through the same seal in Contact with the roll 66 and guide rolls 68 and 69 in a continuous movement. A

On the rolls 64 and 66 I preferably employ wipers 70, 70, though these of course may be omitted without departing from my invention.

y `The rollers 64 and 66 tit the roll housing 71 sosnugly that little water or otherA liquid 8, ,can work between these rollers and the housing 71. In this preferred construction whatever water or other liquid 8 works between the roll housing 71 and the roll 64 is caught in the catch basin 72 and flows from there into the well 73.

VVhatex-er liquid 8 works between the roll housing 71 and the roll 66, as well as between the rolls 66 and 65, and between the rolls 65 and 64 is caught in the catch basin The drying of the webin this preferred form is the same as in those'forms previously described.

'In Fig. 8 I have illustrated another modiicat-ion of my invention in which the waterprooi:` carrierbelts78 protects the web 2 by covering and pressing it against the roll 64 in the same manner as in Fig. 7 and Fig. 7. In thisfform, however, the carrier belt is led around the guide rolls 79, 79 within theA i j vacuum chamber A, thence out through the same liquid seal 8 between the rollers 65 and 66, and thence arund the guides 80, mounted on the exterior of the vacuum chamber.

In this form the sealing liquid 8 is located betweenthe rolls 64 and 465 and between the rolls '65 and 66. To prevent air working past the rolls 64 and 66 and the roll housing 81, I use any suitable form of liquid, or solid packing. I have shown for example a liquid packing or seal, as for cxample, water or other suitable liquid, being fed to the liquid seals 82, 82 under pressure. To remove any thin film of water or other liquid which may adhere to the periphery of the roll 64, I mount a wiper box 83 on one side of the liquid seal 82, and another wiper box 183 on theotherxside of the liquid seal 82. The wiper 83'is connected bythe pipey 84 so that any'liquid which vmay be removed by the wiper 83 will drain into the well 74.

Any liquid 8 removedby the wiper 183 is permitted to drain into the room, as yfor example by permitting it to drain through the pipe 184, and catching it in any suitable manner (not shown).

The wiper boxes 83 and 183 cooperating with ,the rolls 64 and 66 are drained in the same manner, the wipers 83, 83 into the well 7 4`and'the wipers 183, 183 through the pipes 184` 184 to the atmosphere where the liquid is caught and led away in any suitable manner (not shown).

-I may use one ormore wipers 85, though these may be dispensed with if desired. The catch basin 86 will catch any liquid 8 which may leak, drip, seep or flow intol the vacuum chamber between the rolls 64, 65 and 66. Such liquid is led from the catch basin by the ipe 87 and permitted to flow into theiwell 4.

A similar seal may be used at the exit passage (not shqyvn) or any other form of seal may' be Aused,`\it of course being understood that the seals-at the entrance and exit pas-- sages need not necessarily be duplicates, as previously pointed out.

In some cases I may use two carrier belts.

I have shown suchan arrangement in Fig. 9 where I employ an upper water proof carr1er belt 88 and a lower waterproof carrier belt 89. In this form of my invention, I use four sealing rolls 90,91, 92 and 93, The up per carrier belt 88 passes around the guide roll 94 andvthen through the bite between the rolls 91 and 92, protecting the u perportion of the web 2, and thence aroun the sealing roll 92 incontact with the sealing roll 93, around the guide roll 95 and back to the guide roll 94. The lower carrier belt 89 passes from the guide roll 96 in contact withl the sealing roll 91, around the guide roll 9 7 and back between the rolls 90 and 91 to the guide roll 96. As the web2 of paper, or similar material, passes through the sealing liquid andbetween the sealing rolls 91 and 92, it is protectedby both the upper and lower ,waterproofv carrier belts 88 and 89, see Fig. 12.

To catch any water or other sealing liquid 8, which may drip, seep or work through into the vacuum chamber A, I employ Each of thesetraps has connected therewith a pipe 102 which permits any liquid collected bythe tra-ps to drip, seep or flow into the well 74, from which it is withdrawn by the pipe 60 and the barometric seal 13. The liquid may be permitted to run to waste. or be pumped back vby the pump 15 and the pipe 103 to the rolls 90, 91, 92 and 93.

The web 2, after it enters the vacuum chamber A, is freed from the lupper and lower carrier .belts 88 and 89 and passes the water traps 98, 99, and 101.

around one or more drying drums or cylinders 19, 20, 21, 22 uand 23 in the same manner as previously described. The dry web is then passed out of the exit passages through a duplicate or other suitable sea] in which the same sealing liquid, or any` other suitable liquid may be employed.

I have shown lanother modification of my invention in Fig. 1,0, in which the sealing rolls 104, 105 and 106 are formed of different diameters, 105 being smaller than the others. In this form, the sealing iud 8 of water or 'other liquid is located between the sealing rolls 104 and 106 and above the intermediate sealing roll 105. To prevent any'air working around the sealing roll 104,'

I locate someof the sealing -liquid 8 above .that roll and between it and the roll housing 107. To protect the other roll 106 I provide the housing 107 with a water seal 108. Water under pressure, depending upon the degree of Vacuum in the vacuum chamber A, is Jforced into this water seal 108. I also mount wipers 109 and 110 in the housing. The wiper 109 is connected' by. the pipe 111 with the water trap 112. The wiper vv110 may be drained in any suitable manner. These wipers will remove any thin ilm of water which may adhere to the 'seals 131, 131'.

periphery of the sealing roll 106. That removed by the wiper 109 drips into the water trap 112 'from which it is removed by the pipe 113.

In this form of my invention, I use a single carrier belt 114, which passes over tnc guide roll 115 and protects the web 2 of paper, or other similar material, by pressing it tightly against the periphery of the sealing roll 106. The carrier belt is then passed over the guide rolls 116, 117 sealing roll 105 back to the guide roll 115. To catch any Water or other sealing liquid 8, which may be employed, I use the water trap 112, which may be emptied in any suitable manner, as by a pipe 113, which drains into the well 118. I may also employ a wiper 119 bearing upon the sealing roll 104. Any liquid that this wiper may remove from the sealing roll 104 will also lfall into the well 118, from which it is drawn off in any suitable manner as, for example, by the pipe connecting with the barometric seal 13. The liquid 8 may be permitted to run to waste,

or if desired for any reason it may be withdrawn from the barometric seal 13 by the pipe 14 and pumped by the pump 15 and pipe 103 back to the roll housing to be again used, as shown in Fig. 10.

I have shown another modification of my invention in Fig. 13. .In this figure I use three sealing rolls 120, 121 and 122 and one waterproof carrier belt 123. The web 2 of paper, or other suitable material, is fed over the guide roll 124 and thence in contact with the sealing roll 122 through the sealing liquid 8. Before the web 2 passes through the sealing liquid 8 of Water, or other suitable liquid, it is protected by the waterproof carrier belt 123, which presses it against the periphery of the sealing roll 122.

After the web2 has passed from the sealing rolls 121 and 122, it is withdrawn from the protecting waterproof carrier belt 123 and passed around the guide roll 125 and thence around the drying drums or cylinders 19, 20, 21, 22 and 23. After the endless waterproof carrier belt 123 has protected the web of paper 2, while it passed through the liquid seal 8, the carrier belt is then passed over the guide rolls 126, vi127', through the bite between the sealing rolls 120 and 121,' to the guide rolls 128 and 129, its movement being continuous.

In this form of my invention, I provide the roll housing 130 with t-wo liquid The pressure of the water or other liquid in these seals 131, 131 will depend upon the degree of vacuum maintained in the vacuum chamber A as previously described. In the housing 130,l I also provide two' wipers132 and 232. The wipers 132, 132 are connected with their respective drain pipes 133,133 and drain into the well 134. The wipers 232, 232 are connected with their respective drain pipes 233, 233 and drain into-the room Where tht` liquid 8 is collected and removed in any suitable manner (not shown).

The liquid 8 in this form of my inven tion, as well as in the other forms, is not meant to flow between the sealing rolls 120, 121, 122. However, some of the Water or other similar liquid will drip, seep or work into the chamber cr well 134. I withdraw this liquid in any suitableA manner from this chamber and permit it to run to Wastethrough the pipe 135 or again use it, as may be found the most economical practice.

In this form of my invention I haveshown the exit passage 4 of the'vacuum chamber A equipped with the same form of seal as the entrance passage 3, though, of course', it is to be understood thatany suitable seal and sealing liquid may be used at the exit, and that such seal does not necessarily have to be identical with that at the entrance passage to the vacuum chamber, all as previously eX- plained in connection with other forms of my invention.

i My invention is particularly adapted to be used in connection with drying sheet materials in the form of paper, though it is to be distinctly understood that it is equally applicable to and covers drying sheet material in the form of textile fabrics, as for example, drying such fabrics after they have been washed or bleached or dyed, or otherwise treated by a liquid of some description.

My method possesses many advantages not present in processes heretofore used for many years in the drying of paper.

The evaporation process, which is characteristic of the so-called loft drying of paper, has many fully recognized disadvantages, and yet it is used today and has been in use for many years. In this method the wet paper is taken from the paper machine, cut into sheets, hung on poles, carried to the drying room where it is subjected tohot air at about 130 F. for about 48- hours, and when dry, each sheet is separately calendered. Although possessing the advantage of drying at a comparatively low temperature, whereby the moisture is slowly evaporated, loft drying is obviously very ineiiicient and costly, because it requires many separate manipulations, is extremely slow, uses extensive floor space and 'wastes heat.

The process which is employed in the ordinary paper machine in common use, is likewise subject to many disadvantages. In such machine, the wet paper as it comes from the paper machine, is passed over many re volving cylinders, heated internally by steam to suiciently high degree of heat, to raise the temperature of the water in the paper to 212 F., the, atmospheric boiling point of water. Itis customary to supply the drying -cylinders with steam at approxi- 'mately' pounds gauge pressure, at which the steam has a temperature of 228 F., giv-f ing a difference of temperature (228-212) of only F. With this slight difference j of temperature the transfer of heatis extremely slow, and hence it is necessary to employ many drying cylinders, in board machines often one hundred, and in news print.

machines, forty or more.

Also due to convection land conduction losses, as well as those incident to leaks in the piping system and other ineiiciencies, the heat actually required for atmospheric drying of 'a ton of wet paper, is very much 1n excess of theftheoretical requirement. The

'thermal efliciency of atmospheriedrying by steam heated cylinders is therefore very low.

Furthermore, the steam produced from boily exceedingly disagreeable and unhealthy atmosphere in which to work. It is well known that the minimum temperature 212, the atmospheric boiling point of water,` is positively injurious to, and results in oxidizing, the fibres of the paper," the strength of which is vastly improved when the paper is dried at lower temperatures, as in loft drying. This atmospheric drying process requires large initial cost for cylinders, felts, and other necessary equipment, and extensive floor space, and results in the consumption of large amounts of power, and great cost for operation, maintenance and repairs.

Some of the modern open air dryers are equipped with a blower system by which air, either heated or not, is blown through the dryer section, which will lower thel temperature at which 'the water is evaporated from the paper much below 212 F., and may, in some cases, reduce the temperature of evaporation as low as 180 F. of lower.

In my improved vacuumdrying method I contemplate maintaining within the chamber a vacuum of about 28. of mercury, in which water boils at 100 F., and supplying the drying cylinders with steam at 5.3 pounds gauge pressure, producing a temper` ature of 228 F. The temperature difference between the temperature of the steam in the cylinders and that of the paper,lis therefore, 128 F. in my vacuum method, or 8 times greater (16 F. 8:128 F.) than the temerature difference in atmospheric drying. n'my improved method the paper dries approximately y8 times faster than in atmospheric drying, and I require only about oneeighth the number of drying cylinders to dry paper at'the same rate of speed. VI am able to dry kpaper with 5 cylinders in the same time required of 40 cylinders drying at atmospheric pressure, resulting. in great economies in'cost of the machine, floor space and of necessary piping, felts, auxiliary equipment, and particularly in power and maintenance charges. i

The thermal efficiency of myv vacuum method is very much 'greater than that of the atmospheric cylinder .drying heretofere in luniversal use for drying paper. Theoretically, it requires about 4287 pounds of steam to dry one ton of paper at atmospheric pressure, but to compensate for convection and conduction losses, and those due to leaks in the piping system, and other inefciencies, it has been shownin practice that about 10,600 pounds are required.

In my method, using a vacuum of about 28, the convection, conduction andpiping losses are exceedingly small and the total steamv required to dry a ton of paper by my method is approximately 5200 pounds.

-It is an established fact that paper dried at low temperatures is much stronger than when it is dried at the high temperatures used in paper machine atmospheric drying. Paper dried in a vacuum of28, or at a. temperature of about F. as in my method, is very'much stronger than paper dried at atmospheric pressure, when the steam in the driers is at 228 -F. When paper is dried by my method, therefore, a

cheaper furnish or stock can be used and still produce apaper equal in strength to atmospheric dried paper, in which a higher grade furnish'or stock is used. In making newsprint paper, I am able to dispense with a considerable portion of the more expensive sulphite pulp, as this can be replaced with the cheaperv ground wood pulp. By my method I also reduce the number of breaks in the web as it passes over the cylinders.

Furthermore, in my method there is a great saving of heat (or steam) because the process is carried o-n in a vacuum chamber which acts on the principle of a thermos bottle, and the steam and'vapor's driven out of the wet paper are caught in the closed lvacuum chamber, and conduct-ed away to the condenser. The operating room is free from steam, humidity and neat, and fans,

and exhausters are dispensed with. Inthe use of my method thel apparatus is at all times operating under definite humidity', the control of the drying can be closely standardized, and vthe ,moisture content in the aper carefully regulated.

aving pointedl out the many advantages of my method and apparatus over those heretofore used, it will be apparent that the use of my invention results in great economy in the initial cost of apparatus and l 1n large savlngs 1n cost of operation, maintenance and repairs."

Having thus described this invention in connection With different illustrative embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired to secure by Letters Patent is set forth in the appended claims.

What I claim is 1. The method of sealing a vacuum chamber having openings for the passage of material to be treated, consisting in partially closing each opening against the adm'fssicn of air by means of one or more rotating members mounted iny each opening, and substantially sealing by means of a liquid said openings against the admission of air.

2. The methodofsealing a vacuum chamber having openings for the passage of materials to be treated, consisting in partially closing each opening with one or more rotating members and rendering each opening substantially air tight by means of a moving dripping or seeping liquid.

3. The method of sealing a vacuum chami ber having openings for the passage of material to be treated, consisting in partially closingleach opening with one or more rotating members and rendering each opening substantially air tight by means of a liquid Working into .the vacuum chamber, andu withdrawing any liquid that may work into the vacuum chamber.

4. The method of sealing a vacuum chamber having openings for the passage of mar terial to be treated, consisting in partially closing each opening with one or more rotating members and rendering eacli opening substantially air tight by means of a liquid working into the vacuum chamber andcirculating the liquid so that the same liquidcan again seal the opening in the vacuum chamber.

5. The method of sealing a vacuum chamber having openings f or the passage of material t be treated, consisting in partially closing each opening each against the admission of air by means of one or more rotating members mounted in each opening, and substantially sealing by means of water said openings against the admission of air.

6. The method of sealing a vacuum chamber having openings' for the passage of material to be treated, 'consisting in partially closing each opening with one or more rotating inembers'mounted in the openings and rendering each opening air tight by means of moving dripping or seeping water.

7. The method of continuously drying any material, consisting in continuously feeding thematerial into and out of a vacuum chamber through restricted passages the walls of each of which are formedin part by one or more `rotating members, and passing a liquid through therestricted passages, the liquid forming a seal and substantially preventing the admission of air into the vacuum chamber, and drying the material in the vacuum chamber.

8. The method of continuously drying sheet material consisting in continuously feeding the sheet into and out of a vacuum chamber through restricted passages the Walls of ea '.-h of which are formed in part by one or more rotating members, and passing aliquid through the restricted passages, the liquid walls of which are formed in part by one or more rot-ating mgmbers, passing a liquid r and the sheet through the restricted pas sages, the liquid forming a seal and substantially preventing the admission of air into the vacuum chamber, guiding the sheet matei'ial over one yof the rotating members and drying the sheet material in the vacuum chamber.

l0. The method of continuously drying a web of sheet material, consisting in continuously feeding the sheet into and out of a vacuum chamber through restricted passages the walls of each of which are formed by one or more rotating members and non-rotating members, passing the sheet around one of the rotating members and permitting liquid to work through said restricted passages to seal said passages" and substantially preventing the admission of air into the vacuum chamber, and drying the web in the vacuum chamber.

11. The method of continuously drying sheet material consisting in continuously feeding the sheet into and out of a vacuum chamber through a restricted. passagethe walls ofeach of which are formed in part by one or more rotating members and at the same time feeding a protecting carrier belt through said restricted passage and out again through the same restricted passage, feeding a sealing liquid through said restricted passage to render the same substantially air tight, and drying the `web in the vacuum 13. In a vacuum drying apparatus the 'v combination 1n a vacuum chamber having an entrance passage of movable means mounted in said entrance passage and sub-u vstantially closing said passage,and a fluid to seal said passage against the entrance of air into the vacuum chamber.

14. In a vacuum drying apparatus the combination in a vacuum chamber having an entrance passage of movable means mounted in said entrance passage and sub-v stantially closing said passage, and a fluid to seal said passage against the entrance of air into the vacuum chamber and drying means mounted in the vacuum chamber.

15. In a vacuum drying apparatus the combination of a vacuum chamber having an entrance passage for the admission of material to be treated in the vacuum chamber, one or more rotating members mounted in the passage and tending to prevent a sealing liquid working into the vacuum chamber, and a sealing liquid to prevent air working around the rotating members ,into the vacuum chamber.

16. In a vacuum drying apparatus the combination of a vacuum chamber'l having entrance and exit passages one or more rolls in each passage, a liquid to substantially close each passage against the admission of air into the chamber, drying means mounted in the vacuum chamber and one or more carrier belts adapted to pass through the liquid and protect the material to be dried from contacting with said sealing liquid.

17. In .a vacuum drying apparatus the combination of a vacuum chamber having entrance and exit passages to permit the continuous passage of she-etmaterial to be treated into and out of the vacuum cham' ber, one or more rolls mounted in each entrance and exit passage to partially close said passage, a liquid in the said passage which, with the roll or rolls, renders the said passage substantially air tight, and means mounted in the vacuum chamber to dry the sheet materialas it passesvth'rough the said chamber.

18. In a vacuum drying apparatus the combination of a vacuum chamber, one or more drying drums or cylinders in the chamber, moving dripping or seeping fluid seals to seal the entrance and Yexit passages of said chamber, means to cause the luidto move drip or` seep one or more carrier belts to protect the material treated while passing through said Huid seals, and

a separate felt and guiding means therefor' for each drying drum or cylinder to compensate for the diierent shrinkage on each drying drum or cylinder.

19. In a vacuumv drying apparatus the combination of a vacuum chamber having entrance and exit passages, means to dry the material treated in the vacuum chamber, fluid seals rendering the passages substantially air tight, and a Aplurality of interlocking carrier belts to receive between them the material to be dried and protect said material from coming in contact with the fluid of the fluid seals and guiding means for the belts.

20. In a paper drying machine the combination with a web feed roll, of a ,doctor eo- `acting therewith, and a liquid supply means connected with the doctor to supply liquid thereto to afford a liquids seal between the doctor and said roll.

21. In combination with a vacuum web drier machine comprising a drier housing having openings therein, a plurality of rolls andv doctors closing said openings, and liquid sealing means connected with said doctors.

22. In combination with a vacuum web drier machine comprising a drier housing having-openings therein, a plurality of contacting rolls in said openings, and liquid sealing means supported from said housing 'and contacting twovof said rolls to aiord a non-leaking seal.

ODGEN MINTON. 

